net: sctp: Fix typo in net/sctp

Correct spelling typo in net/sctp/socket.c

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>